Determination of organochlorine pesticide residues in water, sediment, and fish samples from the Meriç Delta, Turkey

Abstract

This study had been carried out between May 2002 and August 2003 in Meriç Delta, Turkey which is located at a site where the Meriç River falls to the Agean Sea. Residues of organochlorine pesticides (OC) in surface water, sediment, and fish (Cyprinus carpio) samples from Meriç Delta were analysed by gas chromatography. The results of the study showed that all analysed 20 organochlorine pesticides and their residues have been widespread throughout the study area. According to the results, it was found that the concentrations of these selected organochlorine pesticides in fish (Cyprinus carpio) samples were higher than in water and sediment samples. Because of the low water solubility of the organochlorine compounds, it is expected that any organochlorine pesticides present in the study area, will be preferably adsorbed to sediment or bioaccumulated in fish. The α- and β-HCH were the predominant HCH isomers in all analysed fish samples and ranged between 319.5 and 968.15 ng g⁻¹ and between 397.5 and 876.4 ng g⁻¹, respectively. The concentration levels of p,p′-DDT (ranging from 2.68 to 52.45 ng g⁻¹) in all analysed fish samples were consistently higher than its metabolite p,p′-DDE, indicating a recent use of this organochlorine pesticide in the area. We have analysed the distribution characteristics of individual organochlorine pesticide and found that α-, β-HCH, p,p′-DDT p,p′-DDE, β-endosulphan, heptachlore epoxide, and endrin ketone were the most common organochlorine pesticides contaminants in the study area.

Keywords:

• Meriç Delta
• Organochlorine pesticides
• Residue
• Biota

Acknowledgements

The present study was supprted by the Scientific and Technical Research Council of Turkey, which is highly appreciated. The authors thank Celal Ferdi Gökçay of the Environment Engineering Lab., Middle East Technical University (METU) – Ankara, for analytical detection of OCs concentrations.